﻿/*
 * [The "BSD licence"]
 * Copyright (c) 2005-2008 Terence Parr
 * All rights reserved.
 *
 * Conversion to C#:
 * Copyright (c) 2008-2009 Sam Harwell, Pixel Mine, Inc.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

namespace AntlrUnitTests
{
    using Antlr.Runtime;
    using Microsoft.VisualStudio.TestTools.UnitTesting;
    using NotImplementedException = System.NotImplementedException;

    [TestClass]
    public class TestLookaheadStream
    {
        [TestMethod][TestCategory(TestCategories.Antlr3)]
        public void TestSeek()
        {
            UnbufferedTokenStream stream = new UnbufferedTokenStream(new TokenSource());

            stream.Consume();
            Assert.AreEqual(0, stream.LA(-1));
            Assert.AreEqual(1, stream.LA(1));

            stream.Mark();

            stream.Consume();
            Assert.AreEqual(1, stream.LA(-1));
            Assert.AreEqual(2, stream.LA(1));

            int index = stream.Index;
            stream.Rewind();
            Assert.AreEqual(0, stream.LA(-1));
            Assert.AreEqual(1, stream.LA(1));

            stream.Seek(index);
            Assert.AreEqual(1, stream.LA(-1));
            Assert.AreEqual(2, stream.LA(1));
        }

        private class TokenSource : ITokenSource
        {
            int count = 0;

            public string SourceName
            {
                get
                {
                    return "test";
                }
            }

            public IToken NextToken()
            {
                return new CommonToken(count++);
            }


            public string[] TokenNames
            {
                get
                {
                    throw new NotImplementedException();
                }
            }
        }
    }
}
